1

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

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Radiation Hardened, High Performance Industry

Standard Single-Ended Current Mode PWM

Controller

ISL78840ASRH, ISL78841ASRH, ISL78843ASRH, ISL78845ASRH

The ISL7884xASRH is a high performance, radiation

hardened drop-in replacement for the popular 28C4x and

18C4x PWM controllers suitable for a wide range of

power conversion applications including boost, flyback,

and isolated output configurations. Its fast signal

propagation and output switching characteristics make

this an ideal product for existing and new designs.

Features include up to 13.2V operation, low operating

current, 90µA typ start-up current, adjustable operating

frequency to 1MHz, and high peak current drive

capability with 50ns rise and fall times.

Specifications for Rad Hard QML devices are

controlled by the Defense Supply Center in

Columbus (DSCC). The SMD numbers listed in the

ordering information must be used when ordering.

Detailed Electrical Specifications for the

ISL788xASRH are contained in SMD 5962-07249. A

“hot-link” is provided on our website for

downloading.

Features

• Electrically Screened to DSCC SMD # 5962-07249

• QML Qualified Per MIL-PRF-38535 Requirements

•1A MOSFET Gate Driver

• 90µA Typ Start-up Current, 125µA Max

• 35ns Propagation Delay Current Sense to Output

• Fast Transient Response with Peak Current Mode

Control

• 9V to 13.2V Operation

• Adjustable Switching Frequency to 1MHz

• 50ns Rise and Fall Times with 1nF Output Load

• Trimmed Timing Capacitor Discharge Current for

Accurate Deadtime/Maximum Duty Cycle Control

• 1.5MHz Bandwidth Error Amplifier

• Tight Tolerance Voltage Reference Over Line, Load

and Temperature

• ±3% Current Limit Threshold

• Pb-Free Available (RoHS Compliant)

Applications

• Current Mode Switching Power Supplies

• Isolated Buck and Flyback Regulators

• Boost Regulators

• Direction and Speed Control in Motors

• Control of High Current FET Drivers

Pin Configuration

ISL78840ASRH, ISL78841ASRH,

ISL78843ASRH, ISL78845ASRH

(8 LD FLATPACK)

TOP VIEW

PART NUMBER

RISING UVLO

MAX. DUTY CYCLE

ISL78840ASRH

7.0

100%

ISL78841ASRH

7.0

50%

ISL78843ASRH

8.4V

100%

ISL78845ASRH

8.4V

50%

8

7

6

5

2

3

4

1

COMP

FB

CS

RTCT

V

REF

V

DD

OUT

GND

December 21, 2009

FN6991.0